The present invention relates to a control system, and in particular to a control system for a motor vehicle.
Control systems for motor vehicles command various actuators of the motor vehicles to perform certain tasks. Examples of control systems include traction control systems, anti-lock braking systems and stability control systems. Each of these control systems has a particular function that is carried out when certain information is sensed by the vehicle. For example, the anti-lock braking system will prevent the tires of the vehicle from locking during braking. Furthermore, vehicle control systems coordinate some or all of the actuators of the vehicle to produce a desired vehicle movement or procedure.
Heretofore, total control structures for motor vehicles have included coordinating elements which convert a command from a higher hierarchical level into commands for elements of a lower hierarchical level. The contents of the commands, which are transmitted from above to below in the hierarchical structure, define physical variables that determine the interfaces between the individual hierarchical levels. The command flow is only from a higher hierarchical level to a lower hierarchical level. U.S. Pat. Nos. 5,351,776 and 6,154,688 disclose control systems wherein the command flows only from the higher hierarchical level to the lower hierarchical level. However, the aforementioned control systems do not revise their commands to the lower hierarchical levels when the actuators being commanded by the lower hierarchical levels cannot carry out the commands.
Accordingly, an apparatus solving the aforementioned disadvantages and having the aforementioned advantages is desired.
One aspect of the present invention is to provide a method of controlling a suspension of a vehicle with a suspension coordinator subsystem. The method includes inputting a suspension behavior modification demand signal into the suspension coordinator subsystem, with the suspension behavior modification demand signal requesting a suspension behavior modification. The method also includes determining first capabilities of the first actuator control subsystem and outputting a first capability signal from the first actuator control subsystem to the suspension coordinator subsystem, with the first capability signal communicating the first capabilities of the first actuator control subsystem. The method further includes calculating a first partial suspension behavior modification demand signal and at least one second partial suspension behavior modification demand signal. The method also includes the step of outputting the first partial suspension behavior modification demand signal from the suspension coordinator subsystem to the first actuator control subsystem and the at least one second partial suspension behavior modification demand signal to at least one second actuator control subsystem. Both the first partial suspension behavior modification demand signal and the at least one second partial suspension behavior modification demand signal are calculated according to the first capabilities of the first actuator control subsystem. The first partial suspension behavior modification demand signal and the at least one second partial suspension behavior modification demand signal provide directions for the first actuator control subsystem and the at least one second actuator control subsystem, respectively, to perform the suspension behavior modification of the suspension demand signal.
Another aspect of the present invention is to provide a method of controlling a suspension of a vehicle. The method includes the step of providing a suspension coordinator subsystem configured to modify the suspension of the vehicle and at least one accompanying coordinator controller configured to modify other components of the vehicle that affect vehicle motion. The method further includes the steps of outputting an output signal from at least one accompanying coordinator controller, calculating a demand signal, inputting the demand signal into the suspension coordinator subsystem, and modifying the suspension of the vehicle according to the demand signal. The demand signal is calculated in response to the output signal from the at least one accompanying coordinator controller.
Yet another aspect of the present invention is to provide a suspension control system for controlling a suspension of a vehicle. The suspension control system includes a suspension coordinator, a first actuator control subsystem and at least one second actuator control subsystem. The suspension coordinator subsystem includes at least one subsystem input for receiving a suspension behavior modification demand signal and a subsystem output, with the suspension behavior modification demand signal requesting a suspension behavior modification. The first actuator control subsystem includes a first actuator input and a first actuator output. The at least one second actuator control subsystem includes a second actuator input. The first actuator control subsystem determines its first capabilities and outputs a first capability signal out of the first actuator output to the at least one subsystem input of the suspension coordinator subsystem, with the first capability signal communicating the first capabilities of the first actuator control subsystem. The suspension coordinator subsystem calculates a first partial suspension behavior modification demand signal and at least one second partial suspension behavior modification demand signal. The suspension coordinator subsystem outputs, through the subsystem output, the first partial suspension behavior modification demand signal into the first actuator input of the first actuator control subsystem and the at least one second partial suspension behavior modification demand signal into the second actuator input of the at least one second actuator control subsystem. Both the first partial suspension behavior modification demand signal and the at least one second partial suspension behavior modification demand signal and are calculated according to the first capabilities of the first actuator control subsystem. The first partial suspension behavior modification demand signal and the at least one second partial suspension behavior modification demand signal provide directions for the first actuator control subsystem and the at least one second actuator control subsystem, respectively, to perform the suspension behavior modification of the suspension demand signal.
Accordingly, the vehicle control system provides for enhanced redistribution of functionality to avoid a loss of performance of the vehicle. The vehicle control system is easy to implement, capable of a long operable life, and particularly adapted for the proposed use.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.